The below-mentioned Patent Document 1 discloses a knee airbag for a vehicle in a configuration that is provided with a lower inflation portion that protects a knee area forward portion and a shin area of a seat occupant and an upper inflation portion that protects a knee area upward portion of the seated occupant. A thickness of the upper inflation portion is made thinner than the lower inflation portion by a pair of straps. Thus, a gas pressure inside the upper inflation portion is made lower than a gas pressure inside the lower inflation portion.
It is stated that, according to the knee airbag device for a vehicle with the configuration described above, because the upper inflation portion is provided, the knee area upward portion of the seated occupant may be protected, and because the upper inflation portion is thinner and has a lower internal pressure than the lower inflation portion, a load on the lower leg of the seated occupant may be reduced.
Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2004-122922
Patent Document 2: JP-A No. 2003-175793
Patent Document 3: JP-A No. 2005-186887
Patent Document 4: JP-A No. 2008-126974
Patent Document 5: JP-A No. 2009-083617
Patent Document 6: JP-A No. 2010-052457